Electrical coupling device particularly for electric heating appliance stands



Sept. 23, 1948. 2,450,336

, T. J. ELECTRICAL COUPLING DEVICE PARTICULARLY FOR ELECTRIC HEATING APPLIANCE STANDS Fi-led Feb. 4, 1946 Patented Sept. 28 1948 was when. a umen; than pplicati'on reoruaiyi, 1946,'s na1no.-e45,437

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" scr m (01521955 This invention relates to electric couplingappliances for supplying electric kettles; electr'ic irons and like portable appliances which require to betemporarily connected to supply mains from time to time and which are commonly provided with flexible supply conductors attached to a plug connector for insertion into a wall-socket or the like.

The "flexible conductors commonly used for supplying "the' current to portable appliances, particularlyfor domestic use, are a source of con siderable inconvenience and of some danger, owing to the fact that the flexible conductors quickly-deteriorate in use and-*the ordinary user usually fails to notice the deterioration of the flexible conductor, orat any rate negle'cts'to rem edy it, until a definite fault resulting in breakdown oraccident occurs.

The present invention provides a new or improved coupling device which dispenses with the usual flexible supply conductors and'enables the appliance to be'connectedto and disconnected from the supply. mains with complete safetyi The invention consists in the combination of a shelfor support for an" electrickettle or other appliance to be connected to the mains; asocket connector mounted on the shelf of-infixed rem: tiO l theretoand adapted to cooperate witha plug connector on the appliance arranged so that the pins of the plug connector can be inserted into the socket elements of the "socket connector by "a sliding movement of the appliance upon the sheli or other support, and 'a switch device controlling the supply of current to the socket connector and adapted to be operated by the engagement of a switch operating member with a projection provided on the appliance and arranged-so that the action'oi pushingthe plug} connector on the appliance into the socket member turns on the switch whilst the action of withdrawi g. the plug onnector turns, ofi. the switch. The saidsheu i made or metal or i Provided with ametallic surface arranged to make contact with a metalpart of the appliance when the latter is placed on the Shelf or. support to provide a protective earth connectiontherefor. V v

"The invention will now be described with reference to the accompanying drawingswhi'ch show one example of an apparatus according to the invention and in which:

Figure 1 is a longitudinal sectional view. of the appliance and shows an electric kettle standin thereon, a v ,1

Figure 2 is a transverse section onthe line 2' ofmguril ,fldis pivotally so Figure S' is a side'elevation-partly broken-away and-shows an-electric-iron in the place of the kettle shown in Figure l.

The device shown-in the drawing comprises a shelf- I" of generally rectangular shape and a casing-orhousing :2 mounted on the shelf a soasto project upwards from the rear end thereof and leaving suflicient room to enable akettle; electric iron or similarappliance to' be-stood upon the shelf in front of the'cas'ing 2. I

As shown in the drawing, theshelf I is made wholly of metal and this construction is preferred but, if desired, '-the shelfmay beoi composite construction providing a metallic surface to make contact with-a metallic part of the appliance to be stood thereonso' as toprovide a-protective metallic continuity to-earth as will" hereinafter befurther explained; The casing 215' also preferably made entirely of metal; butit" would be, possible to'llse other materials if preferred;

The shell? I may be fixed toawall or other support. If desired it may be attached to a cooker soas to project, for example, fromtheside thereof. Inorder to'facilitate the mountingoi the shelf in a desired position, the casing. 2 may be provided'witha cable entry opening '3 in the-rear wall thereof and-acable entry opening 4 at the bottom thereoi, suitable removable closures such as that shown at i bein provided for closin the cable entry openingif required; This enables the main supply to be introducedeither through the rear wall of the casingl or. through'the bottom of the device as xnay'b most convenient and, when the device is fixed tothe side'of a cooker, it may conveniently be supplied with current through a flexible metallic conduit such asthat indicated at I 6 in Eigure 1. One end of this conduit may be secured as for, example by screwing containing the power supply. conductors to the cooker.

Mounted in the casing 2 on the front wall thereoi'is a combined two-pin socket connector and doubleeuole tumbler. sw t h m u n a 9017- celain-or-other insulating body 1 and arranged to be wired sothat-in-one position of thei'switchthe socket terminal connectors-8, are connected to the mains whilst in the other-positionof-the switch both socket" terriiinal connectors.- 8 areis0lated from themainsn The operating leverq of-the tumblerswitch is pivotallyconnectedto a pair of toggle links 1 0 and H. The-link 0 o 'f telescopic construct on "ted at "bn'fid ti)" the -lever 9 and at the other end to a bracket I 2 fixed to the front wall of the casing 2 above the switch, a coiled spring I3 being arranged so that it tends to lengthen the telescopic link I and to rock the lever 9 downward as seen in the drawing so as to open the switch. The link II is pivotally connected at one end to the .lever 9 and at the other end to a switch operating lever I4 which is pivotally attached to the front wall of the casing 2 and projects rearwardly therefrom beneath the switch.

The operating lever I4 is shaped so that it forms a cam surface adapted to cooperate with a metal foot or projection I5 fixed to the base of an appliance such as the electric kettle shown in Figure 1. The front wall of the casing isprovided with an opening to receive the feet or projection I5 and the arrangement is such that, when this foot or projection is pushed through the said opening into the interior of the casing 2, the lever I4 is rocked in an upward direction against the spring I 3 and moves the switch to the closed position.

Any number of kettles, electric irons or other appliances may be provided for use with the device and each such appliance is provided with a plug connector comprising terminal pins, one of which is shown at I6 in Figure 1, mounted near the base of the appliance in such a way that, when the appliance is stood on the shelf I,

the pins I6 can be made to enter the socket connectors 8 by sliding the appliance on the self I towards the casing 2. Each appliance is also provided with a foot or projection I5 as hereinbefore mentioned and this foot or projection is arranged in relation to the pins I6 so that, as the appliance is pushed in a rearward direction to cause the pin I6 to enter the socket connectors 8, the foot or projection I5 operates the lever I4 so that the switch is moved to the closed position against the action of the spring I3.

Each electric kettle provided for use with the device is preferably provided with three feet by which it can be stood upon a table or other surface. Two of these feet may be of metal or other material and one of these two feet can be seen at I! in Figure 1 of the drawing. The third foot is formed by the foot or projection I5 previously referred to and, as previously indicated, is arranged in relation to the pin I6 so that it will operate the lever I4 when the pins are inserted into the socket member.

In order to facilitate the proper insertion of the pin I6 on the kettle into the socket terminals 8, the shelf I is provided with three grooves I8 (see particularly Figure 2 of the drawings) which extend in a fore-and-aft direction from end to end of the shelf I and which are arranged to receive the feet I5 and I! of the kettle and to guide the same when it is pushed rearwardly on the shelf so as to bring the pin I6 into engagement with the socket terminals 8.

The foot I5 is made of metal and is in metallic continuity with the body of the kettle so that the body of the kettle is electrically connected to the shelf I (or to the metallic surface provided thereon as hereinbefore mentioned) when the kettle is placed on the shelf. It is thus impossible to break the continuity between the body of the kettle and the shelf I or the metallic surface provided thereon until the switch controlled by the lever I4 has been moved to the off position and the pins I 6 have been withdrawn from the socket connectors. The shelf I, or the above mentioned metal surface thereon, is of 4 course to be permanently connected to earth in any approved manner.

Electric irons or other appliances provided for use with the device will also be provided with pins I6 adapted to enter the socket connectors 8 by a sliding movement of the appliance upon the shelf I and also with a, foot or projection I5 arranged to operate the lever I4 as hereinbefore described and provision is made in each case to ensure electric continuity between the body of the appliance and the shelf I or metallic surface provided thereon. Figure 3 shows an electric iron stood on the table I, electric continuity between the iron and the shelf I or metal surface provided thereon being ensured both by thecontact of the flat bottom of the iron with the shelf or the metallic surface thereon and also by the engagement of the foot or projection I5 between the lever I4 and the shelf I.

As illustrated in Figure 2, the under-surface of the shelf I is provided with a number of grooves I9 adapted to receive a number of irons so that the latter can be conveniently stored under the shelf by pushing them into the grooves t9 as shown in Figure 2 so that they will be suspended therefrom.

In order to avoid any possible danger of shock or damage due to contact of a foreign body with the pins I6 when in connection to the mains, these pins may be insulated over about half their length so that when the pins are partially engaged with the socket connector, for example as illustrated in Figure 1, only insulated parts of the pins project in front of the wall of the casing 2. The socket connectors 8 are made of such length and are so arranged that contact between the bare parts of the pin I6 and the socket' connectors 8 cannot occur until the bare parts of the pins I6 have disappeared entirely into the insulating body I. All danger of shock or damage due to portions of the pin I 6 projecting in front of the casing 2 whilst the pins are still live is thus avoided.

The part shown at 20 in Figure 1 is a pilot lamp mounted in the casing 2 on the bracket I2 and connected to the socket terminals 8 so as to be lighted when the current is switched on to the socket terminals 8. A window 2I is provided on the front of the casing 2 so as to enable the light of the pilot lamp to be seen and it will be evident that this arrangement provides a convenient indication to the user that the current is switched on.

I claim:

1. An electric coupling device for connecting an electric heating appliance such as a kettle to the electric mains, comprising the combination of a support having a housing upstanding from the rear end thereof, a socket connector comprising an insulated body mounted within the housing and having sockets opening in the front wall and located above an entrance aperture into said housing, socket terminals mounted in and inset from the mouth of the sockets, a complementary plug connector having terminals projecting'from said appliance, a grooved guide extending from front to rear of said support towards the front wall of the housing for slidable engagement with the appliance to guide the plug terminals into the sockets, a guard shroud on one of said connectors which covers the plug terminals and electrically insulates them from external connection during engagement with or disengagement from the socket terminals, a, projection on the appliance arranged to pass through the apertured entrance in the housing as the plug terminals move into the sockets and an electric switch device in said housing and having a spring returned operating member so disposed in relation to the apertured entrance in the housing that it is moved by the projection to close the switch during the engaging movement of the plug terminals into the socket terminals.

2. An electric coupling device according to claim 1, wherein the projection on the appliance for operating the switch operating member is constituted as feet to the appliance which slidably engage in the grooved guide in the support.

3. An electric coupling device according to claim 1, wherein the underside of the support opposite to that side which contains the grooved guide is provided with a grooved support formed to receive and hold the base of an electric iron in inverted position.

4. An electric coupling device for connecting an electric heating appliance such as a kettle to the electric mains, comprising the combination of a support having a housing upstanding from the rear end thereof, means for earthing the appliance during connection to the mains including a projection on the appliance and a grooved guide on the support in which the projection is slidable, a socket connector with two mains socket terminals mounted on the front wall of said housing, a complementary plug connector having terminais projecting from said appliance, an electric switch device in said housing and having a spring returned operating member located adjacent to an aperture in the front wall of said housing, the said guide, projection, connectors and operating member being arranged so that the plug terminals are guided into engagement with the socket terminals by the projection engaging in the guide and the projection passes through the aperture to move the operating member to close the switch while a positive earth connection is maintained throughout electrical connection of the connectors, and a guard shroud on the plug connector which protects and electrically insulates the bare parts of the plug terminals from external connection while the said plug terminals are engaged with, the socket terminals.

THOMAS JOHN HALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

